6 Applications of Reaction Injection Molding (RIM)

6 Applications for Reaction Injection Molding (RIM)

The RIM process is commonly used to fabricate low volumes of large, complex parts, making it well-suited to industrial and commercial products that require intricate or bulky components.

Here are a few of the most common applications of reaction injection molding:

1. Products Exposed to High Temperatures

Household and kitchen appliances as well as some medical devices tend to generate heat. While products made from the thermoplastic resins used in traditional injection molding could warp, melt, or damage electronics when exposed to heat, RIM products have incredible heat resistance. That makes reaction injection molding ideal for products exposed to higher temperatures.

2. Products That Need to be Durable and/or Chemically Resistant

RIM products are resistant to heat, water, and chemicals like corrosive acids and solvents. Additionally, they are highly durable because the resulting polyurethane plastic parts are more resistant to wear and tear than products produced by injection molding. Heavy equipment consoles, medical device covers, recreational vehicles, and other products with plastic parts can benefit from the durability and chemical resistance of RIM.

3. Products with Complex Parts and Varying Wall Thicknesses

The RIM process is well-suited for creating parts that require design flexibility, such as analytical machines in the medical field, electrical enclosures, or panels and doors for a variety of plastic parts. With the low viscosity materials used in the process, manufacturers can use intricate molds to construct highly complex parts with curves, encapsulated components, and more. 

Similarly, RIM-produced parts can have varying wall thicknesses. While injection molded parts must be uniform in order to prevent the part from deforming as it cools, RIM allows for varying wall thicknesses within the same part without built in stress, sink or distortion in the part.

4. Large Component Manufacturing

Thanks to its ability to handle complex designs, deep draws, strength-to-weight ratio, and smooth, cosmetic finishes, RIM is a popular choice for large component manufacturing, such as automotive bumpers, large covers for machines such CT’s or MRI’s, gas pump covers and mass transit fare vending covers.    

Producing a large component through injection molding requires the production of several smaller parts that then need to be assembled to create the whole product. Alternatively, manufacturers can use RIM to produce one large component - eliminating the costs and resources required to assemble smaller injection molded parts into one larger piece.

Especially in smaller volumes of less than 5,000 units, RIM is a low-cost option for manufacturing large components.